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true teeth in a sentence

1. While tadpoles do not have true teeth, in most species, the jaws have long, parallel rows of small keratinized structures called keradonts surrounded by a horny beak.

2. Tadpoles lack true teeth, but the jaws in most species have two elongated, parallel rows of small, keratinized structures called keradonts in their upper jaws.

3. Lacking true teeth, it had an array of white bristles on its upper lip and two keratinous plates within its mouth for chewing.

4. Fossils findings of juvenile placoderms, which had true teeth that grew on the surface of the jawbone and had no roots, making them impossible to replace or regrow as they broke or wore down as they grew older, proves the common ancestor of all gnathostomes had teeth and place the origin of teeth along with, or soon after, the evolution of jaws.

5. Placoderms were also the first fish to develop pelvic fins, the precursor to hindlimbs in tetrapods, as well as true teeth.

6. A study of the arthrodire Compagopiscis published in 2012 concluded that placoderms (at least this particular genus) likely possessed true teeth contrary to some early studies.

7. At first it was suspected these structures were not true teeth at all, but later research established they were built like normal teeth, including enamel, dentine and a pulp.

8. They have teeth made of bone, rather than the true teeth of other fishes, and the males have a pair of boney fangs which the use for sparring for mates.

9. Britz et al. believe the lineage lost true teeth about 50 Ma.

10. Upon maturity, the tiny males of most species metamorphose into a parasitic form, which lacks both a lure and true teeth and is presumed not to feed.

11. Gastrotheca guentheri (Guenther's marsupial frog) is the only known frog with true teeth in its lower jaw.

12. True teeth are unique to vertebrates, although some invertebrates have analogous structures sometimes called "teeth".

13. The major differences between them were that holocephalians have shagreen on their skin and ptyctodontids did not, that the armored plates and scales of holocephalians are made of dentine, and the armored plates and scales of ptyctodontids were made of bone, the anatomy of the craniums of holocephalians is more similar to sharks, and that of ptyctodontids were more similar to those of other placoderms, and, most importantly, the holocephalians have true teeth, while the ptyctodonts had beak-like tooth-plates.

14. Most of the common names refer to these birds' most notable trait: tooth-like points on their beak's edges, which, unlike true teeth, contained Volkmann's canals and were outgrowths of the premaxillary and mandibular bones.

15. Unlike the true teeth of Mesozoic birds like Archaeopteryx or Aberratiodontus, the pseudoteeth of the Pelagornithidae do not seem to have had serrated or otherwise specialized cutting edges, and were useful to hold prey for swallowing whole rather than to tear bits off it. Since the teeth were hollow or at best full of cancellous bone and are easily worn or broken off in fossils, it is surmised they were not extremely resilient in life either.

16. It has been suggested at times that the "teeth" of pelagornithids were homologous with true teeth on an at least molecular level, being derived from the same programs responsible for the formation of teeth in other dinosaurs.

17. Gastrotheca guentheri is the only known frog with true teeth in both of its jaws, as indicated by the name of the genus it originally typified, Amphignathodon, described by George Albert Boulenger in 1882.

18. Gastrotheca guentheri is the only known frog with true teeth in its lower jaw.

19. No true teeth are present.

20. Previously it was thought that the dentary of Andreolepis did not contain true teeth, but instead harbored denticles.

21. Aquatic larvae have true teeth on both upper and lower jaws, and external gills.

22. Tadpoles also lack true teeth, but the jaws in most species usually have two elongate, parallel rows of small keratinized structures called keradonts in the upper jaw while the lower jaw has three rows of keradonts, surrounded by a horny beak, but the number of rows can be lower (sometimes zero), or much higher.

23. The dracula fish is unusual in that its ancestors lost their true teeth around 50 million years ago, but re-evolved its bone fangs as a replacement around 30 million years ago.

24. While not true teeth in the usual sense, the dermal denticles of sharks are almost identical in structure and are likely to have the same evolutionary origin.

25. Indeed, teeth appear to have first evolved in sharks, and are not found in the more primitive jawless fish – while lampreys do have tooth-like structures on the tongue, these are in fact, composed of keratin, not of dentine or enamel, and bear no relationship to true teeth.

26. True teeth are unique to vertebrates, although many invertebrates have analogous structures often referred to as teeth.

27. The anodont hinge is characterized by a strong ligament (or a series of transverse ligamental grooves as in the Isognomonidae), however, true teeth are absent in adults as is the case in the pen shells (Pinnidae), tree oysters (Isognomonidae), the pearl oysters (Pteriidae), and some freshwater mussels such as the genus Anodonta.

28. The Carapace is unknown, and besides that has preserved bowed converging sides with a curved posterior margin with straight posterior border of the labium , with row of at least 12 peg teeth along Cheliceral Furrow, no true teeth, scattered setae on anterior surface, slender Pedipalps.

29. Sawfish evolved long snouts armed with rows of teeth on both sides, although these spines do not represent true teeth, but highly modified fish scales, or dermal denticles.